Date   
Re: OT: QService components

 

Hi Dennis,
Someone else mentioned QService is out of business
I think you're referring to Stefans T.'s message. He wasn't referring to QService:

Lol, we had a very small electronics mail order here, over the years
> you could smell how his habit increased.
> The man is out of business now.
I've been a non-smoker all my life. I've purchased a few items from QService, one being a pretty large PCB (TDS520 logic board) in an antistatic bag. I can't remember them smelling of smoke.

Raymond

Re: Hello from new member w 2465A issues

Tothwolf
 

On Mon, 25 Jan 2016, edbreya@... [TekScopes] wrote:

Those paper AC line X-caps have been the subject of much discussion here and on the hpagilent group. They are the ones potted in amber colored epoxy, usually WIMA or RIFA brand. The bottom line is that they should be eliminated whenever encountered - even if not already failed - and replaced by proper X-rated plastic-dielectric caps. This is especially important in high line voltage (~240V) countries, where the caps are operating near their limit.

These are also used inside of some packaged line filter assemblies, and known to have caused internal failures there.
Rifa brand, not Wima. Wima has never made those translucent yellow X and Y type safety capacitors. Kemet now owns Rifa and continues to make these paper insulated safety capacitors, however I will not use them and generally replace them with Epcos film types of the same safety class (X or Y, it matters).

Re: Recommendations / 2247A

 

For what it is worth, I hear about fewer problems with the 4 channel
22xx oscilloscope than the 2 channel 22xx oscilloscopes and the 24xx
oscilloscopes. They seem to be more reliable although my 2247A does
currently have a problem that I have not tracked down. Apparently the
reference clock for the timer/counter is intermittent and I suspect
the clock crystal or oscillator is failing. I just have not gotten
around to fixing it.

The 4 channel 22xx oscilloscopes are also fully documented and parts
mules are inexpensively available making them easy to maintain.

The 2247A will not really do anything that your 2236 cannot but it has
a lot of user features. They both have a gated universal
timer/counter which is the big feature for these models. The 2247A
adds cursors, voltage measurements, and gated voltage measurements.

As I posted earlier, the 2247A series does *not* use digital
calibration so it does not have the loss of calibration issues of the
24xx series oscilloscopes which might be considered an advantage.

If I did *not* already have a 2247A, then I would want a 2236 for the
gated universal timer/counter.

The 2252 is not as common but it has all of the same features and for
practical purposes is the same as a 2247A.

On Mon, 25 Jan 2016 12:19:43 -0600, you wrote:

I did not realize the 2236 has a 6802.

Thanks for your comments, David and Malcolm.

John

Re: Hello from new member w 2465A issues

Ed Breya
 

I remember there were at least two brands that made those or similar caps. I looked up WIMA and found this example:

http://www.wima.com/EN/mp3x2.htm http://www.wima.com/EN/mp3x2.htm

They look a little different, but I think they're the kind I recall seeing in the past. I don't remember if I had seen any failures of this brand, but I assumed that they're close enough to the same as the RIFAs, which I've seen fail a few times - perhaps because they're more common.

Regardless of what the makers say in the specs, much experience here indicates that very messy catastrophic failures can occur with paper X-caps, with bangs, meltdowns, and noxious fumes - but perhaps no fires, which is the main point. The X-rated caps are for across-line use, so don't have shock hazard issues. The Y-rated are for line to ground, so could. I don't recall ever seeing this style of cap in a Y-application, only X, although it looks like they're available. I wouldn't trust them for any use - I've purged my stock of these long ago.

Ed

Two AM 503 CP Amps for parts or refurb

Bill (Doc) Courtright
 

Hello,
I am trying to clean house a bit here. I have two AM 503 Current probe amps that are complete except for one latch but both have a smoke film mainly on one side due to a smoky fire elsewhere in my former storage area.
One is SN B031467 with a tan board and some leaky caps the other is B064903 newer with a green coat board and is clean on the component side. This one should be salvageable.
I would like $20 plus shipping for the pair. Due to their condition I would rather not put up on the auction site. Can e-mail pix on request.
Thanks,
Bill
KB3DKS

Re: Two AM 503 CP Amps for parts or refurb

 

I'll take them if still available.

Regards,
Tom WA3PZI

----- Original Message -----
From: Doxemf doxemf@... [TekScopes]
To: TekScopes@...
Sent: Monday, January 25, 2016 4:28 PM
Subject: [TekScopes] Two AM 503 CP Amps for parts or refurb



Hello,
I am trying to clean house a bit here. I have two AM 503 Current probe amps that are complete except for one latch but both have a smoke film mainly on one side due to a smoky fire elsewhere in my former storage area.
One is SN B031467 with a tan board and some leaky caps the other is B064903 newer with a green coat board and is clean on the component side. This one should be salvageable.
I would like $20 plus shipping for the pair. Due to their condition I would rather not put up on the auction site. Can e-mail pix on request.
Thanks,
Bill
KB3DKS

Re: OT: QService components

Torch Fireman
 

On 25/01/2016 3:06 PM, 'Dennis Tillman' @Dennis_Tillman_W7PF [TekScopes] wrote:

Apparently we have a lot of non-smokers in the forum
judging from the comments I am seeing.
If you read the "Tektronics and You" employee manual, you will discover that the tobacco smoke smell is OEM. ;-)

Re: CL: Lot of 5 Tek 453's

 

They seem to be more reliable although my 2247A does
> currently have a problem that I have not tracked down. Apparently the
> reference clock for the timer/counter is intermittent and I suspect
> the clock crystal or oscillator is failing.
I have both a 2247A and a 2252. I like them a lot. I just wish their bandwidth would be larger.

My 2252 came with a problematic counter function. The PLL circuitry in the Slow Counter Logic IC (U1902) appeared bad.
As a test, I replaced the circuit with a simple XOR-based external PLL. It works so well that I decided not to go for a more elaborate solution.

Raymond

Tektronix TDS754D Fail++ Processor error + firmware

bddicch
 

Hello i have a TDS754D with a Fail ++ Processor error, from my experience with my TDS544A it was in that version part of recap job. and nvram failure.




To pinpoint this problem to the right direction. can it be a "dead NVRAM" ? ( after 10 years ) . i heared from other people the TDS754D version boards A10 and A11 have no smd cap problems.-> recapping not neccesary so not the problem with this A11 Dram Processor board.


can someone post a hex file from TDS754D NVram, (my options: 13,1F,2F,2C )


help wanted to solve my problem and hex file

2247A 2252 Timer Counter Reference

 

On 25 Jan 2016 13:53:02 -0800, you wrote:

They seem to be more reliable although my 2247A does
currently have a problem that I have not tracked down. Apparently the
reference clock for the timer/counter is intermittent and I suspect
the clock crystal or oscillator is failing.
I have both a 2247A and a 2252. I like them a lot. I just wish their bandwidth would be larger.

My 2252 came with a problematic counter function. The PLL circuitry in the Slow Counter Logic IC (U1902) appeared bad.
As a test, I replaced the circuit with a simple XOR-based external PLL. It works so well that I decided not to go for a more elaborate solution.

Raymond
That would be a much more involved repair than just a bad crystal or
bad oscillator. I hope that is not the problem with mine.

There number of things which could go wrong in that circuit including
the Motorola level shifters which I hear are known to be unreliable.
Usually with oscillators I find that the problem is the crystal.

When I run the detailed self diagnostics, they pretty much point
directly to a missing 100 MHz reference.

Re: CL: Lot of 5 Tek 453's

 

It's been a while and I didn't take notes but I remember that I could see that the phase info (U1902 PFC, pin 23) was dead (steady state). Of course, I first looked at TC1 (pin 1) and VCO (pin 26) and found both alive and well, so the X-tal oscillator and U1904D (level shifter) couldn't be the problem. Partly just for confirmation of my conclusion, I decided to just cut pin 23 (PFC) and put in one gate of a socketed 'LS86 between pins 1, 26 (inputs), and 23 (output). Works a treat! As said, a bit rough but accurate and stable. I think that i didn't even put in a pull-up resistor at pin 23, which strictly speaking shouldn't be necessary but may improve shape and level. Of course, a bit of HF jitter does no harm in this application and is actually inserted through pin 22 (Noise).

Raymond

Re: CL: Lot of 5 Tek 453's

 

What? This post ended up in the wrong thread! Sorry about that, please ignore!

Raymond

Re: CL: Lot of 5 Tek 453's

 

It's been a while and I didn't take notes but I remember that I could see that the phase info (U1902 PFC, pin 23) was dead (steady state). Of course, I first looked at TC1 (pin 1) and VCO (pin 26) and found both alive and well, so the X-tal oscillator and U1904D (level shifter) couldn't be the problem. Partly just for confirmation of my conclusion, I decided to just cut pin 23 (PFC) and put in one gate of a socketed 'LS86 between pins 1, 26 (inputs), and 23 (output). Works a treat! As said, a bit rough but accurate and stable. I think that i didn't even put in a pull-up resistor at pin 23, which strictly speaking shouldn't be necessary but may improve shape and level. Of course, a bit of HF jitter does no harm in this application and is actually inserted through pin 22 (Noise).

Raymond

Re: CL: Lot of 5 Tek 453's

 

And again, it lands here! It should be in the "2247A 2252 Timer Counter Reference" thread!

Raymond

Re: CL: Lot of 5 Tek 453's

 

Sorry, I give up. No use fighting against a Yahoo.

Raymond

Re: 7603 weirdo inverted Z axis

 

I checked it again and the voltage was low because the sweep was set
to 50ns/div where the beam is blanked for a significant amount of
time. At most sweep speeds, the maximum voltage was about 75 volts
and at the slowest sweep speeds where the Intensity Limit is
activated, the voltage was about 50 volts.

On 25 Jan 2016 07:39:37 -0800, you wrote:

Hi David,

From 15 V to 28 V seems a rather small change compared to the data in the calibration section. Maybe you set the time base for a slow speed that activates the Intensity Limit?
Albert

============

With Q1107 (a slow 2N3904???) removed on my 7603, the output at point
B is 14.8 volts which closely agrees with our current calculation so I
wonder if Marian's <public@... mailto:public@...> measurement of 20 volts at the
output of the z-axis amplifier is significant and indicates a problem.
I get the same 14.8 volt output with Q1107 installed, the readout off,
and the intensity control turned to minimum.

I also measured the output at point B and as the intensity control is
turned fully clockwise, the output increases to about 28 volts
monotonically.

help wanted ..console port or service port for TDSxxx

bddicch
 

Hello can someone help me out and tell me how to connect to the console port from my tds scope.
it is the 2x10 edge connector on the processor PCB.


building an adapter to connect the RS232/Centronics board (option 13) to that connector. required pin assigment is:

Console port -Opt Board - Signal Name
A10 - 1 (D24)
B10 - 3 (D25)
A9 - 5 (D26)
B9 - 7 (D27)
B8 - 2 (D28)
A7 - 4 (D29)
B7 - 6 (D30)
A6 - 8 (D31)

B1 - 21 (A1)
A1 - 23 (A2)
B2 - 25 (A3)
A2 - 22 (A4)
+5V 24 (A5)
GND 26 (A6)

B5 - 12 (INT#)
B4 - 15 (IOCS#)
A5 - 16 (SYSRESET#)
A4 - 17 (RNW)
+5V - 18
+5V - 11

A8 GND
B6 +5V


but these are the pins from the console port connector. My question howto connect to this port to my laptop and open a terminal console over the RS232 port.


any body can help me out and give more info?

Re: OT: QService components

Brad Thompson <brad.thompson@...>
 

On 1/25/2016 3:06 PM, 'Dennis Tillman' @Dennis_Tillman_W7PF [TekScopes] wrote:

Hi Malcom,
I have bought from them several times and never encountered a tobacco smell.
I would have remembered if I had, since I have been a non-smoker all my
life. My dad was a lifelong cigar smoker and I can't stand the smell of
cigars to this day. Apparently we have a lot of non-smokers in the forum
judging from the comments I am seeing.
<snip>

Hello--

Back in the late 1980s, I served as a technical editor for Test & Measurement World magazine
which shared open-office space with EDN magazine, both Cahners publications at that time.
Cahners had an explicit "smoking allowed" policy, and a certain EDN editor smoked cigars.

As a nonsmoker I recall asking, on several occasions, "Is that a good cigar, or do I smell a transformer fire?"

It was unclear whether the editor in question was Not Amused, but he couldn't fire me<g>.

(Come to think of it, a transformer fire smells better than a cigar....)

73--

Brad AA1IP

Re: help wanted ..console port or service port for TDSxxx

David DiGiacomo
 

On Mon, Jan 25, 2016 at 3:54 PM, <bddicch@...> wrote:

Hello can someone help me out and tell me how to connect to the console port from my tds scope.
it is the 2x10 edge connector on the processor PCB.


building an adapter to connect the RS232/Centronics board (option 13) to that connector. required pin assigment is:

Console port -Opt Board - Signal Name
A10 - 1 (D24)
B10 - 3 (D25)
A9 - 5 (D26)
B9 - 7 (D27)
B8 - 2 (D28)
A7 - 4 (D29)
B7 - 6 (D30)
A6 - 8 (D31)

B1 - 21 (A1)
A1 - 23 (A2)
B2 - 25 (A3)
A2 - 22 (A4)
+5V 24 (A5)
GND 26 (A6)

B5 - 12 (INT#)
B4 - 15 (IOCS#)
A5 - 16 (SYSRESET#)
A4 - 17 (RNW)
+5V - 18
+5V - 11

A8 GND
B6 +5V


but these are the pins from the console port connector. My question howto connect to this port to my laptop and open a terminal console over the RS232 port.

The option 13 board has a DB9M connector on it:
http://www.qservice.tv/vpasp/shopexd.asp?id=8987

You just hook up a DB9F to DB9F serial cable between the board and the
laptop's serial port: http://www.monoprice.com/product?p_id=448

Re: 2247A 2252 Timer Counter Reference

 

After several failed attempts to put the following reply in the thread "2247A 2252 Timer Counter Reference" I'm trying via the general "Conversations" page. Previous attempts landed in the "C: Lot of 5 Tek 453's" thread.

My apologies if this doesn't work either.

It's been a while and I didn't take notes but I remember that I could see that the phase info (U1902 PFC, pin 23) was dead (steady state). Of course, I first looked at TC1 (pin 1) and VCO (pin 26) and found both alive and well, so the X-tal oscillator and U1904D (level shifter) couldn't be the problem. Partly just for confirmation of my conclusion, I decided to just cut pin 23 (PFC) and put in one gate of a socketed 'LS86 between pins 1, 26 (inputs), and 23 (output). Works a treat! As said, a bit rough but accurate and stable. I think that i didn't even put in a pull-up resistor at pin 23, which strictly speaking shouldn't be necessary but may improve shape and level. Of course, a bit of HF jitter does no harm in this application and is actually inserted through pin 22 (Noise).

Raymond